Combined reversing-switch and brush-holder for dynamo-electric



C. BERGMANN, JR. v

COMBINED REVERSING SWITCH AND BRUSH HOLDER FOR DYNAMO ELECTRIC MACHINES.

APPLICATION FILED OCT- I4. I915.

1,195,768. Patented Aug. 22, 1916.

UNITED STATES PATENT OFFICE.

CARL RERGMANN, In, OF WEST NEW YORK, NEW JERsEY, 'AssreNoR 'ro KNAIP ELEC- TRIO AND NOVELTY 00., OF NEW YORK, N. Y., A CORPORATION on NEW YORK.

Specification of Letters Patent.

Patented Aug. 22, 1916.

Application filed October 14, 1915. Serial NO. 55,807.

To all whom it may concern:

Be it known that I, CARL BERGMANN, J r., a citizen of the United States, and a resident of Vest New York, in the county of Hudson and State of New Jersey, have invented a new and Improved Combined Reversing- Switch and Brush-Holder for Dynamo- Electric Machines, of which the following is a full, clear, and exact description.

This invention relates to dynamo electric machines, and more particularly to a switch for controlling the direction of rotation of the armature.

The invention has for its general objects to improve and simplify the construction and operation of apparatus of the character referred to so as to be reliable and efficient in use, comparatively simple and inexpensive to manufacture, and so designed that the circuit connections can be easily and quickly changed for reversing the direction of rotation of the armature.

A more specific object of the invention is the provision of a combined reversing switch and brush holder in the form of two sets of contacts associated respectively with the brushes, and cooperating with the contacts is a doubled cam capable of occupying three positions, namely,- a neutral position when the power is ofi, a position forforward rotation of the armature, and a position for reverse rotation, the sets of contacts being so designed that either brush may be connected with the positive side of the supply circuit.

With such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be set forth with particularity in the following description and claims appended hereto.

In the accompanying drawing, which illustrates one embodiment of the invention and wherein similar characters of reference indicate corresponding parts in all the views,

versing switch and brush arrangement; and

Fig. 7 is a diagrammatic view of the circuit connections of the motor.

In the present instance the invention is shown in connection with a toy electric motor, but it is to be understood that the invention is not necessarily limited to this use.

Referring to the drawing, 1 and 2 designate the front and back plates of the motor frame, whichplates are connected together by rivet rods 3 or equivalent means. On these rods is the field frame 4, which is equipped with an energizing coil 5, and between the polar portions 6 of the field frame is the revoluble armature 7 which has a three-segment commutator 8 to which the windings 9 are connected. On the front plate of the machine frame are the binding posts 10 and 11 for connection with the supply circuit.

The combined reversing and brush device A consists of a supporting block 12 of insulation which has fastened to its ends contact elements 13 and 14 to which are fastened respectively the brushes 15 and 16. These brushes are strips of spring metal each having its base portion 17 provided with a slot 18 for engagement with the screw 19 which fastens the brush and associated contact to the block 12. 4 To prevent pivotal movementof the brushes on their screws, the associated contact members have their base portions formed with parallel flanges 20 between which the base portions of the brushes engage. The contact members 13 and 14 may be longitudinally split so as to better cooperate with the circuitclosing contacts that cooperate with them. A set of contacts 21 and 21 cooperates with the contact 13, and a set of contacts 22 and 22 cooperates with the contact 14. The contacts 21'and 22 are formed by the extremities of a strip of metal bent into the shape of 'a U,and the contacts 21 and 22 are the extremitiesof a similarly bent strip of metal. These U -shaped structures are fastened to the block by the members thereof passing upwardly through vertical openings in the block 12, and by bending the contact members laterally they are effectively held in place without the necessity of special fastening means. Normally the sets of spring contacts are separated from their associated contacts 13 and 14., and by engaging the appropriate spring contacts of each set with the associated brush-engaged contacts 13 and 14, the direction of current through the armature can be controlled for producing forward or reverse rotation. 'The operation of the spring contacts is efiected by a double lobed cam 24 which is fastened to a shaft 25 journaled in an opening 26 in the front plate of the frame and in a post 27 fastened to the rear side of the block 12. On the front end of the shaft is a crank handle 28 for turning the cam in one direction or the other, the movement of the crank handle 28 being limited by stops 29 formed by forwardly extending lugs on the front plate of the motor frame. The combined reversing switch and brush holder is fastened to the front plate 1 of the frame by a screw 30.

The binding post 10 is connected by a wire 31 with the front spring contacts 21 and 22, the wire being soldered to the bottom part or connecting portion 32 of these contacts. One terminal of the field winding 5 is connected by a wire 33 with the bottom or connecting portion 34 between the rear spring contacts 21 and 22 while the other terminal of the field is connected by a wire 35 with the binding post 11.

When the cam of the reversing switch is in neutral position, as shown in Figs. 4, 6 and 7 the motor circuit is opened, but when the crank arm or handle 28 is turned to the right, the cam takes the position shown in Fig. 5, whereby the rear spring contact 21 and the front spring contact 22 are engaged respectively with the contacts 13 and 14, so that the right-hand brush becomes positive according to the diagram shown in Fig. 7, and the armature rotates clockwise, as shown in Fig. 5. When the crank arm is turned to the left from its neutral position the cam 24 causes the front spring contact 21 and the rear spring contact 22 to engage the contacts 13 and 14, respectively, so that the left brush becomes positive and the armature rotates in the reverse direction, as shown in Fig. 3. It will be noted that the cam is approximately on a dead center when it is thrown to either of its operative positions, so that it will remain in either of its three positions until it is manually shifted.

From the foregoing description taken in connection with'the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains, and while I have described the principle of operation, together with the apparatus which I now consider to be the best embodiment thereof, I desire to have it understood that the apparatus shown is merely illustrative and that such changes may be made when desired as fall within the scope of the appended claims.

brushes and consisting of relatively fixed contacts electrically connected with the brushes, a pair of spring contacts associated with each brush and normally separated from the contacts of the brushes, the corresponding contacts of both pairs being electrically connected together, and a device movable from a neutral open circuiting position to either of two closed circuiting posi tions for operating one of each pair of spring contacts in such relation as to close the circuits through the fixed contacts and brushes.

2. In a dynamo electric machine, the combination of a commutator, brushes therefor, a pair of U-shaped contact elements insulated from each other and normally separated from the brushes, and a device located between the members of the said elements for moving the right member of one element and the left member of the other element into electrical connection with the adjacent brushes, or vice versa, for changing the circuit connections.

3. In a dynamo electric machine, the combination of a commutator, brushes therefor, a pair of spaced electrically connected rear contact springs, a pair of electrically connected front contact springs separated from the rear contact springs, and a reversibly rotatable cam operating simultaneously on one of the front contact springs and the opposite rear contact spring for electrically connecting such springs with the associated brushes to change the circuit connections.

4. In a dynamo electric machine, the combination of a commutator, brushes therefor, a pair of spaced electrically connected rear contact springs, a pair of electrically connected front contact springs separated from the rear contact springs, a reversibly rotatable cam operating simultaneously on one of the front contact springs and the opposite rear contact spring for electrically connecting such springs with the associated brushes to change the circuit connections, a shaft on which the cam is mounted, a handle for turning the shaft, and means for arresting theturning of the shaft when the cam is in either of its operative positions.

5. A combined reversing switch and brush device for a dynamo electric machine, comprising a supporting base of insulation, brushes fastened thereto, a pair of U-shaped contact elements having resilient members extending upwardly through the supporting base, with the elements insulated from each other by the latter, the right and left members of the elements being associated respectively with the right and left brushes, and a double lobed cam having its lobes one hundred and eighty degrees apart, whereby one lobe is adapted to electrically connect one of the members of one element with the adjacent brush and the opposite member of the other element with its adjacent brush.

6. A combined reversing switch and brush device for dynamo electric machines, comprising a block of insulation, contact members fastened to the ends thereof and having resilient free portions, brushes fastened in electrical contact with the said members, U- shaped contact elements fastened to the said block and disposed between the said members and normally separated therefrom, one contact element being in front of the other, and a device disposed between the contact elements for moving the right member of one element in engagement with the associated first mentioned member, and the left member of the other element with its associated first mentioned member to control the circuit connections of the brushes.

7 A combined reversing switch and brush device comprising a block of insulation, U- shaped contact elements having spring members extending upwardly through openings in the block, one element being disposed in front of and insulated from the other, spring contact members disposed outwardly from the contact elements and normally spaced therefrom, brushes overlying the said members and clamped against the same, the extremities of the U-shaped elements being bent laterally to hold the same in said block, and a cam having front and rear lobes disposed one hundred and eighty degrees apart and adapted respectively to engage and disengage the front and rear contact elements for moving the latter into and out of engagement with the said members.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

CARL BERGMANN, JR.

Witnesses:

O. BRADWAY, PHILIP D. ROLLHAUS.

Copies of this potent as, be obtained for the cents each, by addressing the "Commissioner of Patents, Washington, D. G. 

